Digital amniotome

ABSTRACT

The digital amniotome described herein is a split-ring like device adapted to be placed on a finger for rupturing the amniotic membrane during obstetrical procedures. The ring-lke device has a recessed portion which is normally positioned to be located at the pad of the fingertip and has a sharp tipped element thereon. Immediately contiguous to the recessed portion is a guard portion which extends out beyond the recessed portion to prevent the sharp tipped element from contacting the amniotic membrane. When pressure is applied to the guard portion, which is resilient, it retracts thereby exposing the sharp tipped element such that it is able to rupture the membrane.

United States Patent 1 Cotey [451 July 31,1973

[ DIGITAL AMNIOTOME [75] lnventorz John Coley, Haddonfield, NJ.

[73] Assignee: Medspec, lnc., Frederick, Md.

[22] Filed: Nov. 18, 1971 [2]] App]. No.: 199,852

[52] US. Cl 128/361, 30/298, 128/329 [51] Int. Cl.. A611) 17/42 [58]Field of Search 128/361, 303 R, 305, 128/314, 329, 330, 333, 215, 253,307, 304; 30/298 [56] References Cited UNITEDSTATES PATENTS 3,687,1398/1972 Porier 128/361 693,554 2/1902 Langstafi'.... 128/333 3,623,47511/1971 Sanz et a1. 128/253 3,126,890 3/1964 Deming 128/361 622,3864/1899 Peery 128/304 OTHER PUBLICATIONS I Stein, .1. A. M. A., Vol. 104,p. 462, Feb. 9, 1935.

Primary Examiner-Dalton L. Truluck Attorney-Mortenson & Weigel [57]ABSTRACT The digital amniotome described herein is a split-ring likedevice adapted to be placed on a finger for ruptur-, ing the amnioticmembrane during obstetrical procedures. The ring-Ike device has arecessed portion which is normally positioned to be located at the padof the fingertip and has a sharp tipped element thereon. lrn- Imediately contiguous to the recessed portion is a guard portion whichextends out beyond the recessed portion to prevent the sharp tippedelement from contacting the amniotic membrane. When pressure is appliedto the guard portion, which is resilient, it retracts thereby exposingthe sharp tipped element such that it is able to rupture the membrane.

5 Claims, 7 Drawing Figures PmmEnm 3. 749.099

mvzzzvroe BY John Coley ATTOBNEK? 1 DIGITAL AMNIOTOME BACKGROUND OF THEINVENTION This invention relates to a digital amniotome, and, moreparticuarly, to a digital amniotome adapted to be actuated by theapplication of pressure thereto.

It is often desirable and/or necessary, for the purpose of hasteninglabor in a pregnant woman who is at term,

to rupture the amniotic membrane. Various devices have been designedover the years for this purpose. One of the more commonly used devicesis a stainless steel member having a finger loop at one end and asharpened hook at the other. Other devices have included surgical gloveshaving a protruding sharpened point positioned on one of the fingers.Still other devices have included finger carried members having a sharppoint on one end and plastic rods having a sharpened hook-like device onone end.

Although the hook-like devices have some advantages over the spearshaped or trocar-pointed devices because there is less change ofinjuring the fetus or traumitizing the patients cervix or vaginal wall,their mere appearance tends to frighten many patients. This isparticularly true of the older stainless steel instruments that areavailable. Furthermore, the sterilization problems encountered with manyof the instruments are difficult and with the increasing labor costsquite undesirable.

It is, therefore, an object of this invention to obviate many of thedisadvantages of the prior art amniotic sac rupturing devices.

There has been described in an earlier filed application filed by JeanR. Poirier entitled Digital Amniotome Ser. No. l10,505 filed Jan. 28,1971 now U.S. Pat. No. 3,687,139 issued Aug. 29, 1972 and assigned tothe same assignee as this application. A digital amniotome whichoperates by movement of the end finger phalanx to cause a hook-likedevice to protrude from a sheath in a finger carried member. While thisdevice has proven quite satisfactory it does tend, because it must beconstructed to be relatively stiff to enhance the fingertip movement, todecrease the obstetricians ability to feel his way during the procedure.With the loss of the sense of feel it is sometimes difficult for theobstetrician to properly operate the device and effect the rupturing ofthe membrane. Further some users encounter some difficulty in flexingthe fingertip as is required.

Accordingly, another object of this invention is to provide an improveddevice for rupturing the amniotic sac during obstetric procedures whichdevice does not inhibit the user's sense of feel.

Another object of this invention is to provide an improved disposabledevice that is easily and quickly used for rupturing the amnioticmembrane during obstetrical procedures.

BRIEF DESCRIPTION OF THE INVENTION the rupture. The device itself is afinger carried member adapted to grip the finger. The member has arecessed portion adapted to engage the end portion of the finger. Asharp tipped element is secured on the recessed portion. The fingercarried member also has a guard portion contiguous to the recessedportion which is adapted to normally extend radially of the fingerbeyond the recessed portion so as to guard or provide a sheath for thehook-like portion. At least one of the portions is resilient such thatany relative pressure between the guard portion and the recessed portionexposes the sharp tipped element to effect the rupture.

Preferably, the finger carried member is in the form of a splitring-like section which is fluted on its rear edge to form fingers whichextend rearwardly along the users finger to more firmly secure thedevice to the finger and prevent movement thereof.

DESCRIPTION OF THE DRAWINGS The novel features that are consideredcharacteristic of this invention are set forth with particularity in theappended claims. The invention, itself, however, both as to itsorganization and method of operation as well as additional objects andadvantages thereof, will be best understood from the followingdescription when read in connection with the accompanying drawings inwhich:

FIG. 1 is a side elevation view of a digital amniotome constructed inaccordance with one embodiment of this invention;

FIG. 2 is a top plan view of the digital amniotome illustrated in FIG.1;

FIG. 3 is a bottom plan view of the digital amniotome illustrated inFIG. 1;

FIG. 4 is a cross-sectional view of the digital amniotome illustrated inFIG. 1 taken along the section line 44;

FIG. 5 is a pictorial view of the digital amniotome in cross-section inposition on the operators finger prior to use; I

FIG. 6 is an illustration of the digital amniotome of this inventionbeing operated to puncture the amniotic membrane, the digital amniotomebeing illustrated in longitudinal cross-section; and

FIG. 7 is a pictorial view of an alternative embodiment of a digitalamniotome constructed in accordance with an alternative embodiment ofthis invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS There is illustrated in FIGS. 1through 4 one embodiment of the invention in which there is seen afinger carried member 10 which has a split ring portion 12 and alongitudinally extended portion 14. The finger member 10 preferably isintegral and may be formed of rubber latex, or any suitable plastic suchas polyamid sold under the trade name NYLON, polytetrafluoroethylenesold under the trademark TEFLON, impact modified polystyrene, or perhapsmost preferably, a polypropylene plastic may be used. Typically the member is formed by molding. Preferably the material forming the member 10is somewhat resilient such that some slight bending or flexure ispermitted, to facilitate the utilization of the device as will becomeapparent from the following description. Portions of the member 10 maybe rigid. The member 10 should be of sufficient length such that thesplit ring portion can fit over the second phalanx of the users finger(usually the middle finger is used for this purpose) with the elongatedportion 14 extending to the general vicinity of the first phalanx orfinger tip. Actually the user can adjust the position to his liking.

The back end of the split ring portion is axially fluted as at 16 forthe purpose of forming axially and rearwardly (along the finger)extending fingers 18. Furthermore, the circular portion of the ringsection 12, which is split as at 20 to permit it to be expanded to fitvarying size fingers, is of a decreasing longitudinal width as the splitregion 20 is approached. This decreasing width in the longitudinaldirection functions to force the fingers l8 inwardly as the circularsplit portion is opened thereby to improve the grip of the device on theusers finger.

The elongated portion 14 is curved axially inward as it extends forward(with respect to the users finger) and has a removed section or cut 22in the general form of an elongated tear drop to form an inner recessedportion 24 on which there is secured a radially extending sharp pointedor hook-like element 26 (FIG. 3 and 4) such that when the hook-likeelement is permitted to come in contact with the amniotic membrane itfacilitates the membranes rupture.

Immediately contiguous to and surrounding the recessed portion 24 is aguard portion or loop 28 which is radially of the users finger moreoutwardly positioned than the recessed portion 24 such that the guardloop 28 tends to sheath and prevent the hook 26 from extending outbeyond the guard loop 28. The hook 26 therefore is prevented from actinguntil guard loop 28 is depressed and thereby exposes the hook. Thecrosssectional area and configurations of the recessed portion 24 andthe guard loop 28 may be varied to vary their relative resiliences.

The normal position of the digital amniotome on the user's finger isseen most clearly in FIG. with the finger tip 30 in contact with therecessed portion 24 such that the hook 26 is recessed relative to theguard loop 28 which is somewhat removed from the finger tip 30. Thefingers 18 are gripping the user's finger, preferably in the region ofthe second finger phalanx, although the member may be constructed to fiton the finger tip if desired, by shortening its over all length. Thesecond phalanx is preferred since the knuckle between the first andsecond phalanxes aids in preventing the axial movement of the digitalamniotome along the users finger.

To use the digital amniotome to rupture the amniotic membrane of apregnant woman in labor, the doctor or other operator places theamniotome on his finger as illustrated in FIG. 5 and inserts theamniotome into the vagina (not shown) and the opening of the cervix (notshown) until the recessed portion and guard loop 28 are immediatelyadjacent the exposed region of the amniotic membrane 32. At the entranceto the cervix, the doctor then by merely pressing the finger tip 30against the amniotic membrane 32 causes the guard loop 28 to retractthereby exposing the sharp tip of the hook-like element 26. With thisaccomplished the doctor merely need draw his finger across the membraneto snag it and thereby cause the rupture with little chance of injury tothe fetus illustrated by the dashed line 32 or to the walls of thevagina or cervix. This accomplished, he merely releases the finger andthe guard loop again snaps back to its original position protecting orguarding the hook 26 and withdraws his finger from the vagina again withlittle or no danger of traumitizing the walls of either the cervix orthe vagina. Being made of plastic it is quite convenient to merelydispose of the amniotome without further ado. No sterilization and reuseare required.

In an alternative usage of the invention, once the finger tip is inposition with the guard loop in contact with the amniotic membrane, thedoctor merely need place his hand upon the pregnant woman's stomach andapply pressure. This causes the amniotic membrane to bulge outwardlyagainst the guard loop depressing the same such that the tip is exposedand the amniotic membrane is then easily ruptured as described hereinbefore.

In the preferred embodiment of this invention both the recessed portion24 and the guard loop 28 are resilient although either may be made rigidas desired. If the guard loop is made rigid, finger tip motion isrequired to extend and expose the hook 26. If both are resilient or evenif only the guard portion is resilient, the guard loop will retract andexpose the hook 26 which is the preferred method of utilization. Noflexing of the finger tip is required as when the guard loop is rigid.As noted hereinbefore some persons encounter difficulty in flexing thefinger tip.

In an alternative embodiment of the invention as seen in FIG. 7 thesplit ring section may be constructed to be of solid form with noextending fingers 18. While this embodiment is not quite as desirable asthe earlier embodiment described herein, it is somewhat cheaper toconstruct and is often preferred by some doctors particularly by thosehaving relatively large fingers where the-additional gripping power ofthe fingers 18 is not required.

In some cases it is preferable to construct the member 10 such that itis radio opaque", i.e., it may be detected using x-rays and the like.This can aid in the recovery of the member in the improbable likelihoodthat it somehow becomes dislodged from the users finger and cannot beimmediately located by probing. This may be accomplished by introducingradio opaque particles in the plastic prior to molding.

While an integral construction is preferred for economy reasons, anypart or parts of the amniotome may be separately constructed as desiredand secured to the remainder of the member as by a suitable adhesive.

There is thus seen to have been described herein an improved digitalamniotome which is relatively simply used without the requirement forflexing the finger. The amniotome described is simple and economical toconstruct and provides a readily used sheathing mechanism that tends toprevent traumitizing the vagina or cervis of the woman.

It is obvious that many embodiments may be made of this inventiveconcept, and that many modifications may be made in the embodimentshereinbefore described. Therefore, it is to be understood that alldescriptive material herein is to be interpreted merely as illustrative,exemplary, and not in a limited sense. It is intended that variousmodifications which might readily suggest themselves to those skilled inthe art be covered by the following claims as far as the prior artpermits.

What is claimed is:

l. A gynecological device adapted to be placed on a finger for rupturingthe amniotic membrane during obstetrical procedures, said devicecomprising:

a finger carried member having a ring-like portion adapted to grip saidfinger,

said member having an elongated recessed portion adapted to be engagedby the end portion of said finger,

said recessed portion having a sharp tipped element secured thereto tofacilitate the rupture of said membrane,

said member also having an elongated generally U- shaped raised guardportion contiguous to and surrounding said recessed portion adaptednormally to protrude radially of said finger beyond said recessedportion, thereby to guard said sharp tipped element,

said recessed portion and said raised portion each being resilientwhereby the relative pressure between said finger tip and said membraneexposes said sharp tipped element to permit the rupture ofcircumferential distance from the split portion thereof. t i i l

1. A gynecological device adapted to be placed on a finger for rupturingthe amniotic membrane during obstetrical procedures, said devicecomprising: a finger carried member having a ring-like portion adaptedto grip said finger, said member having an elongated recessed portionadapted to be engaged by the end portion of said finger, said recessedportion having a sharp tipped element secured thereto to facilitate therupture of said membrane, said member also having an elongated generallyU-shaped raised guard portion contiguous to and surrounding saidrecessed portion adapted normally to protrude radially of said fingerbeyond said recessed portion, thereby to guard said sharp tippedelement, said recessed portion and said raised portion each beingresilient whereby the relative pressure between said finger tip and saidmembrane exposes said sharp tipped element to permit the rupture of theamniotic membrane.
 2. A device according to claim 1 wherein saidrecessed portion and said guard portion have different degrees ofresiliency.
 3. A device according to claim 1 wherein said guard portionis more easily depressed than said recessed portion.
 4. A deviceaccording to claim 1 wherein said device is integrally formed.
 5. Adevice according to claim 1 wherein said finger carried member is aresilient single split-ring section, adapted to fit over different sizedfingers, and the axial length of said ring section increases as afunction of the circumferential distance from the split portion thereof.